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Configuring SNMP
Overview
Simple Network Management Protocol (SNMP) is an Internet standard protocol widely used for a
management station to access and operate the devices on a network, regardless of their vendors,
physical characteristics, and interconnect technologies.
SNMP enables network administrators to read and set the variables on managed devices for state
monitoring, troubleshooting, statistics collection, and other management purposes.
SNMP framework
The SNMP framework contains the following elements:
•
SNMP manager
—Works on an NMS to monitor and manage the SNMP-capable devices in the
network.
•
SNMP agent
—Works on a managed device to receive and handle requests from the NMS, and
sends notifications to the NMS when events, such as an interface state change, occur.
•
Management Information Base (MIB)
—Specifies the variables (for example, interface status
and CPU usage) maintained by the SNMP agent for the SNMP manager to read and set.
Figure 48
Relationship between NMS, agent, and MIB
MIB and view-based MIB access control
A MIB stores variables called "nodes" or "objects" in a tree hierarchy and identifies each node with a
unique OID. An OID is a dotted numeric string that uniquely identifies the path from the root node to
a leaf node. For example, object B in
is uniquely identified by the OID {1.2.1.1}.
Figure 49
MIB tree
A MIB view represents a set of MIB objects (or MIB object hierarchies) with certain access privileges
and is identified by a view name. The MIB objects included in the MIB view are accessible while
those excluded from the MIB view are inaccessible.
A MIB view can have multiple view records each identified by a
view-name oid-tree
pair.
You control access to the MIB by assigning MIB views to SNMP groups or communities.
Agent
NMS
MIB
Get/Set requests
Get/Set responses
and Traps
A
2
6
1
5
2
1
1
2
1
B
Root
